I’m gonna say this:
It is technically possible that he didn’t…
You see, in Hollywood, it’s really simple – you can take the perfect amount of steroids in a short period of time to get your physique to look like a Greek god. Not to mention it’s closely monitored by a medical staff to ensure you can come off cycle with little to no side effects.
So right off the bat, it makes perfect sense for a lot of these actors who land roles where they need a certain body type who can use this cheat code to attain the look the movie requires. They also have a team of people training them in the gym and meal planning and cooking for them. This last part is the key here…
If you take away the steroid usage and just have a small staff of people telling you exactly what movements and exercises to do in the gym and people telling you exactly what to eat and when to eat it, you can literally transform your body into that of a fitness model with one very impressive looking physique.
Now, we need to try to determine if the physique he had for Baywatch is attainable for him, considering his height and weight, juxtaposed to what he looked like before Baywatch.
This is the transformation pic that has been used ad nauseam:
If you look at the left pic, you can see that Zac actually had a decent physique. You can tell he works out but also that being in the gym isn’t his entire life or anything. He is 5’8” and his listed weight is about 165lbs. Let’s say that’s what he is on the left – it seems very plausible.
But what about the pic on the right?
If you really look closely, he doesn’t look that much bigger than before. What you are seeing is a heavy tan (probably spray tan, which is what bodybuilders use before stage competition), much less water retention, and about 10ish more pounds of muscle (landing him around the 175 mark; probably still sub-180). All of these things are easily achievable without steroid usage.
The kicker here is that even with that said, he might have still taken some at the start of his training just to kickstart his body into going from decently cut to finely shredded. But at any rate – if he did take any gear for this role, he did not take a lot, and he didn’t achieve an otherwise unattainable physique. Especially when you combine that with his relative youth at the time and already great baseline physique, I think with proper training and nutrition he would’ve met the same results.
Perhaps if we had an idea of the timeframe he was allowed to get into beach shape, we might be able to make more of an assertion here, but I can’t find any timetable online of how long his training lasted. If it were say, 30 days, I’d lean more towards gear. But even then – he might just be a genetic specimen.
The bottom line here, is that we can never really know unless someone has a blood sample result from that timeframe they’d like to share, but without any evidence, he’s innocent until proven guilty.
I say that he probably did not take any steroids for this role. We just don’t have enough to say it’s obvious he was on gear – while simultaneously I wouldn’t be at all surprised if he was. Nothing about this physique is unattainable for someone with good genetics.
In the case of Zac Efron solely as it pertains to Baywatch, I’ll say it’s a 50% chance.